Break away spline misalignment coupling

Abstract

A torque-limiting coupling may be used to provide a torsion drive between an engine or motor and a driven accessory. If an accessory should experience a catastrophic failure a torsion limit is exceeded and a spline breaks away from the coupling. This guarantees that the internal engine gearing used to drive the accessory is not compromised and interfering with essential moving parts inside the engine. Further, a misalignment compensation limits the side load and wear that occurs when coupling two precision shafts with little clearance on the bearings. With a misalignment coupling, the mount can be slightly out of parallel with no negative effects.

Description

BACKGROUND OF THE INVENTION[0001]It is common for a torsion drive to be employed between an engine and a drive accessory. For example, in automobiles, a belt drive is often used to transfer power from the engine to various accessories, such as a compressor, alternator, generator and numerous pumps. Should any of these accessories experience a catastrophic failure, such as a seized bearing, the accessory will cease functioning and the belt drive will continue to function properly. Although the belt will slip past the non-functioning accessory, possibly causing damage to the belt itself, it is extremely unlikely that damage to other accessories or the engine will occur as a result of the failure of the accessory.[0002]In small aircraft, however, a belt drive is not used to power accessories from an engine. Rather, accessories are driven directly from gears disposed in an accessory case typically located at the rear of the engine. In this design, should a catastrophic failure occur in ...

AI Technical Summary

Benefits of technology

The patent describes a device called a torque-limiting coupling that prevents damage to an accessory from a sudden failure. It uses a spline that breaks away from the coupling if there is a catastrophic failure, protecting the engine's gearing and other moving parts. The device also includes a misalignment compensation that reduces wear and tear when aligning shafts with little clearance. The device has a highly predictable clean break at a specific location in the device, called the neck region, which ensures there is no failure or stripping of drive components. The neck region has a smaller cross-sectional area than the other ends, which can be achieved by creating a bore or reducing the outer diameter.

Problems solved by technology

If the accessory should experience a catastrophic failure, such as a locked bearing or broken rotor shaft, a torsion-limited spline breaks away from the coupling.

Further, misalignment compensation provided by a lobe end limits the side load and wear that occurs when coupling two precision shafts with little clearance on the bearings.

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